Bacteria to Plants
Chapter 5 Seed Plants
Section 1 The Characteristics of Seed Plants
Key Concepts:
1. What characteristics do seed plants share?
2. How do seeds become new plants?
3. What are the main functions of roots, stems, and leaves?
Key Terms:
• Phloem
• Xylem
• Pollen
• Seed
• Embryo
• Cotyledon
• Germination
• Root Cap
• Cambium
• Stomata
• Transpiration
Characteristics of Seed Plants
1.Vascular Tissue
 Most live on land
 Have thick cell walls
 Phloem- Where food moves
 Xylem- Where water and
minerals move
Characteristics of Seed Plants
2. Pollen and Seeds
 Pollen- Tiny structures that
contain cells that will later
become sperm cells
 Delivery system of
sperm cells to egg cells
 Seeds- Form from fertilized
egg cells
 A structure that
contains a young plant
inside a protective
covering
Seed Plants to New Plants
1. Seed Structure
 Embryo- Young plant that
develops from the zygote or
fertilized egg
 Has the beginnings of:
 Roots
 Stems
 Leaves
 Cotyledons- One or more
embryo leaves that can
store food
 Seat Coat
 Skins/wraps on some
seeds
Seed Plants to New Plants
2. Seed Dispersal
 Scattering of seeds
 Some organisms take the
seeds to other places
 Eat and “Dispose” of
seeds later
 Barbed seeds get stuck
on them then fall off
 Water
 Wind
 Light weight seeds
 Some have structures
to catch the wind
 Some explode out seeds
to throw them
Seed Plants to New Plants
3. Germination
 Germination- Occurs when the
embryo begins to grow and
pushes out of the seed
 Does not happen right away
 Seed needs to absorb water
from its environment first
 First roots grow down
 Then stem and leaves grow up
 The further the seed is away
from parent the better chance of
survival
 No competition for the
same resources
Seed Plants: Roots
Purposes of Roots
1. Anchor plants in the ground
2. Absorb water from the soil
3. Absorb minerals from the soil
4. Stores extra food
Seed Plants: Roots
1.Types
 Fibrous root system
 Many similarly sized roots that
form a dense tangled mess
 Take a lot of soil when you pull
them out of the ground
 Lawn Grass, Onion s
 Taproot
 One long, thick main root
 Hard to pull out of the ground
 Carrots, Cacti
Seed Plants: Roots
2. Structure
 Root Cap- Protects the root from
injury from rocks as the root grows
through the soil
Cells that multiple are right
behind the root cap
 Root hairs
Tiny hairs
 Reach into space between
soil particles
Absorb water and minerals
 Grow out of root’s surface
 Help anchor the plant in the
soil
Seed Plants: Stems
1.Two (2) Main Functions
1. Carry substances between
the plants roots and leaves
2. Provide support for the plant
and holds the leaves so they
are exposed to the sun.
(Hermes)
Seed Plants: Stems
2. Structure
 Herbaceous
 No wood- Often Soft
 Woody
 Hard and Rigid
 Several layers of tissue
 Bark= Outer Most layer
 Outer protective layer
 Inner layer of phloem
 Cambium- Divides to produce
new phloem and xylem
 Xylem
 Most of what we refer to as
“wood”
Seed Plants: Stems
3. Annual Rings
 Each ring is made of xylem
Quick Spring Growth
 Large
 Thin walls
 Wide, light brown rings
 Slow Summer Growth
 Small
 Thick Walls
 Thin, dark rings
 Together (each pair) counts as one
(1) year
 Rainy seasons
 More xylem produced
 Wide rings
 Dry seasons
 Less xylem produced
 Narrow rings
Seed Plants: Leaves
Many shapes and sizes
All capture the sun’s energy and
carry out the food making process of
photosynthesis
1.Structure
 Protective top and bottom
layers
 Between layers are veins
containing phloem and xylem
 Surface layers contain
 Stomata- Small openings
or pores
 Act like tiny mouths
 Open and close to
control gases
enter/leaving
 Carbon Dioxide
enters
 Oxygen and water
vapor exit.
Seed Plants: Leaves
2. Photosynthesis
 Contains the most chloroplasts
at the leaf’s upper surface
 Chlorophyll traps the sun’s
energy
 Water is brought to leaves
through the xylem
 Sugar and oxygen are produced
from the carbon dioxide and
water
 Sugar travels through
phloem to feed plant
 Oxygen exists the leaf via
the stomata
Seed Plants: Leaves
3. Water Loss
 TranspirationProcess of water
evaporating out of a
plant’s leaves
 Stomata close to
keep water in the
leaf
Chapter 5 Seed Plants
Section 1 The Characteristics of Seed Plants
1. What characteristics do seed plants share?
2. How do seeds become new plants?
3. What are the main functions of roots, stems, and leaves?
Section Review on p. 145